( CNN) Robert Mueller may not be through with Rick Gates, a deputy Trump campaign aide and one of the four people who have been charged as part of the special counsel probe into Russian meddling in the 2016 election.

“We don't know what the government is going to do, ” Mack said in court, referring to both Gates' case and a white-collar occurrence in New York involving one of Gates' business partners. “I mean, in both cases we've been told that there may be a superseder. We don't know what's happening.”

Mueller charged President Donald Trump's former campaign chairwoman Paul Manafort and his deputy, Gates, on October 30 with 12 alleged crimes related to money laundering and foreign lobbying violations. Both have pleaded not guilty. The charges against Manafort and Gates are unrelated to the Trump campaign, though it's possible Mueller could add additional federal charges.